IGCSE Chemistry 0620 Scheme of Work
Chemistry: Periodic Table 1
Whole Unit Overview
(Please note: (S) denotes material in the Supplement (Extended syllabus) only)
Learning Outcomes Suggested Teaching Activities Resources
6.1 Describe the meaning of exothermic and This can be seen as a rise or fall in temperature endothermic reactions. of many often chemical reactions used in the syllabus.
This concept can be taught across the syllabus, rather than as a discrete lesson.
Suggested experiments:
• neutralisation reactions of acids and alkalis (see Unit 3 Acids - section 8.1)
• metal displacement reactions (see section 10.2 below)
• dissolving salts, including ammonium salts
• if data loggers are available, temperature probes could be used.
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9 Describe the Periodic Table as a method of Elements to be classified as metals and non- Interactive periodic tables: classifying elements and its use to predict metals. Their states should be mentioned. http://www.cs.ubc.ca/cgi-bin/nph- properties of elements. pertab/tab/periodic-table Properties limited to quantitative idea of melting/boiling point. http://www.webelements.com/
Suggested activities: http://chemlab.pc.maricopa.edu/periodic/periodic .html • students make observations from photographic version of periodic table. http://www.dayah.com/periodic/ http://www.chemicool.com/ • a database of properties and states for element of periods 1, 2 and 3 could be http://www.chemsoc.org/viselements/ set up. Students could be asked to design queries to find the metals, non Periodic table teaching site: metal, solids and liquids and enter the http://www.genesismission.org/educate/scimodul results on a blank copy of the periodic e/cosmic/ptable.html table.
9.1 Describe the change from metallic to non- Emphasize the metal/non metal boundary. metallic character across a Period.
9.1(S) Describe the relationship between Group Emphasize number of valency electrons = group number, number of valency electrons and number. metallic/non-metallic character.
10.1 Describe the general physical and chemical Physical properties such as appearance, properties of metals. melting/boiling point, conduction of heat and electricity, malleability and ductility.
Chemical properties such as reactions with water, steam and dilute mineral acids.
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10.1 Explain why metals are often used in the Relate to improvement in corrosion resistance form of alloys. and mechanical properties such as strength.
Link to production of steel (section 10.3a below) and brass.
9.2 Describe lithium, sodium and potassium in Demonstration or video only of reactions with Group 1 as a collection of relatively soft water due to highly exothermic nature. Focus on metals showing a trend in melting point, the observations here. density, in reaction with water.
9.2 Predict the properties of other elements in Include reactions of Rubidium and Caesium and the Group, given data, where appropriate. physical properties such as melting and boiling points. Trends can be obtained from suitable data bases.
10.2 Place in order of reactivity: calcium; copper, Experiments possible include : (hydrogen), iron, magnesium, potassium, sodium and zinc by reference to the Potassium, Sodium with water (as reactions, if any, of the metals with demonstration only)
Water or steam Calcium, Magnesium with water
Dilute hydrochloric acid Magnesium, Zinc with steam
And the reduction of their oxides with carbon. Magnesium, Zinc, Iron with dilute hydrochloric acid.
For advanced candidates this could be extended to (aluminium), lead, nickel, tin and silver to provide a more detailed list of reactivities. (note that aluminium is less reactive than expected in test tube experiments)
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10.2 (S) Describe the reactivity series as related to Experiments possible include : the tendency of a metal to form its positive ion, illustrated by its reaction, if any, with Reaction of the metals magnesium, zinc, iron and copper with aqueous solution of their ions. The aqueous ions, (again (aluminium), lead, nickel, tin and silver The oxides, of the other listed metals. could be added to the list to expand the experiment)
Aluminium and iron(III) oxide (Thermit reaction) as a demonstration of the reactions of metals and oxides.
10.2 (S) Account for the apparent unreactivity of Do not confuse with rusting of iron. aluminium in terms of the oxide layer which adheres to the metal.
10.3(b) Name the uses of aluminium: in the Relate to the uses of aluminium e.g. aluminium manufacture of aircraft because of its is toxic, but oxide layer enables its use for drinks strength and low density and in food cans. containers because of its resistance to corrosion.
10.2 Deduce an order of reactivity from a given Reactions of metals with water, steam and dilute set of experimental results. hydrochloric or sulphuric acid (for advanced candidates also with other aqueous metal ions).
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10.3 (a) Describe the ease in obtaining metals from Electrolysis, carbon + metal oxide and mining of their ores by relating the elements to the native metal as the different methods. reactivity series. Relate these three methods to the position of the metal in the reactivity series.
Possible issues to discuss include
• the economic and environmental cost of the high energy required in metal extraction processes.
• the large input of non renewable fossil fuel resources into electrolysis and carbon reduction.
• the importance of recycling metals.
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10.3(a) Describe the essential reactions in the Key points : use of blast furnace, coke, hot air, Iron and steel manufacture: extraction of iron from haematite. limestone and iron ore and the formation of slag and molten iron. http://www.ohiosteel.org/
Possible issues to discuss include
• local environmental effect of large scale mining of haematite
• the economic and environmental cost of the high energy demand of blast furnace.
• the large input of non renewable fossil fuel resources into carbon reduction.
• the need to collect waste toxic carbon monoxide, which can be used as a fuel to reduce energy cost of plant
• the environmental effect of disposing of slag, and economic issues of searching for a potential use for the waste material
• the need to recycle iron.
10.3(a) Describe the conversion of iron into steel. Use of basic oxygen process (O2 lance) limited to the removal of carbon excess carbon (good example of redox chemistry to illustrate syllabus section 7.3).
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10.3 (b) Describe the idea of changing the properties Use of other elements (often transition of iron by the controlled use of additives to elements) and changing carbon content to alter form steel alloys. properties such as strength and hardness.
Opportunity for data analysis activities to link steel specifications to use.
10.3(b) Name the uses of mild steel (car bodies and Relate to greater resistance to chemical attack machinery) and stainless steel (chemical on stainless steel plant and cutlery).
10.3(a) Describe in outline, the extraction of zinc Key points : roasting in air of sulphide to History of the production of zinc: (S) from zinc blende. produce oxide and then similar process to iron http://www.zincworld.org/ manufacture (except there is no limestone and zinc vaporizes and condenses in pans high in the furnace).
Possible issues to dicuss
• high energy demand of process and input of non renewable fossil fuel
• polluting effects of waste sulphur dioxide and resultant legislative control of roasting in many countries
• the need to recycle zinc.
10.3(b) Name the uses of zinc for galvanising and for Can be expanded to include coinage and (S) making brass. musical instruments.
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10.3(b) Name the uses of copper related to its Properties such as electrical conductivity, (S) properties; electrical wiring and in cooking melting point and general low chemical utensils. reactivity.
Uses can be expanded to include coinage
Link to Unit 8 (Electrochemistry) regarding the purification of copper.
Issues of the need and economic difficulties of recycling of metals could be discussed here.
9.3 Describe the transition elements as a Relevant elements for colours include iron collection of metals having high densities, (valency of 2 and 3), manganese (in potassium high melting points and forming coloured manganate(VII)), chromium (in potassium compounds, and which, as elements and dichromate(VI)) and copper(II). compounds, often act as catalysts. Catalysts to include nickel for hydrogenation of alkenes/fats, platinum in car catalytic converters and iron in the Haber process (also vanadium(V) oxide in the Contact process).
Possible issues to discuss include the importance of catalysts in lowering the energy demand of industrial processes and hence conserving fossil fuel and increasing profitability.
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